The New International Dictionary of Old Testament Theology and Exegesis (NIDOTTE) has the following for תְּרָפִים:
תְּרָפִים (terāpîm), (a) figurines; (b) mask (like “ephod,” it appears to have different meanings in different passages; NIV household gods/idol/idols/idolatry, #9572). The word might be sing. (cf. 1 Sam 19:13, 16) with mimation.
The Theological Wordbook of the Old Testament has the following to say:
ANE Although uncertain, suggested etymologies include רָפָה i, be weak (#8332), or Hitt. tarpiš, spirit, demon.
OT 1. The term functions in a worship setting. In Hos 3:4–5 as punishment Israel will be without a ruler (David their king v. 5), and without Yahweh’s cult items: sacrifice (= altar), pillars, ephod, or teraphim (תְּרָפִים). In deuteronomistic history these words, apart from the teraphim, are standard equipment for a shrine, though condemned by the Jerusalem-centric writer. Similarly the shrine of Micah in Judg 17:5; 18:17, 18 (probably additions here), and 20 has ephod, teraphim, and פֶּסֶל וּמַסֵּכָה.
2. In Gen 31:19, 34, 35 תְּרָפִים appear to be clan emblems, perhaps conferring legal rights of leadership to the possessor. They are small enough to be easily hidden under a person. That the woman was menstruating shows the writer’s contempt for the objects.
3. In contrast, in 1 Sam 19:13, 16 the object is big enough to counterfeit a male body under bed coverings. A translation of “bundle of (worn out?) rags” has been suggested here. This story also mocks the objects; what else are they good for? In neither meaning 2 or 3 are the teraphim associated with a shrine.
4. The object is (like the ephod, but negatively) associated with divination: 1 Sam 15:23; 2 Kgs 23:24 (or is the association here with גִּלּוּלִים?); Ezek 21:21 ; Zech 10:2.
P-B The word continues to be used, albeit infrequently, in later literature.
2545 תְּרָפִים (tĕrāpîm) idolatry, idols, image(s), teraphim. (ASV only “teraphim”; RSV similar to KJV, although rendering “household gods” in Gen 31.)
I hope this is helpful.
Attested fourteen times in OT, the word tĕrāpîm is a plural noun, probably of Hittite origin (so H. A. Hoffner, Jr., in Biblioteca Sacra 124:230–38, and in JNES 27:61–68). In all but one somewhat ambiguous context (I Sam 19:11–17), it is clear that the teraphim of ancient Israel were pagan household idols (cf. Gen 31:19 with 31:30, 32; Jud 18:17 with 18:24), corresponding in many respects to the contemporary ilānu (“gods”) of Nuzi (cf. A. E. Draffkorn in JBL 76:216–24) as well as to the Roman Penātēs; of much later times. Their primary function among the apostate element in Israel’s population seems to have been that of divination (I Sam 15:23; II Kgs 23:24; Ezk 21:21 [H 26]) and make their appearance through the entire sweep of Israelite history, from the patriarchal (Gen 31) to postexilic (Zech 10:2) periods.
Since the discovery and interpretation of certain cuneiform legal documents (notably the one designated as Gadd 51) at the ancient site of Nuzi beginning in 1926, it has become a commonplace to assert, on the basis of such texts, that Rachel stole Laban’s teraphim (Gen 31:17–50) in order to guarantee Jacob’s title to Laban’s inheritance after the latter had died, or at least, to secure for Jacob clan leadership and spiritual power (see, conveniently, C. H. Gordon, The World of the Old Testament, pp. 129f., and in BA 3:5–7). While this view of the matter is intriguing, Nuzi law implies that bequeathal, rather than mere possession, of the household gods determined family leadership. Due to this and other difficulties with the Nuzi theory, it has been suggested that Rachel, not yet fully separated from her polytheistic heritage (see Gen 35:2; Josh 24:2), stole the gods for religious or divinatory purposes. Support for this possibility may be adduced from Jos who, in his Antiquities (18.9.5), states that it was customary even in much later times for inhabitants of Mesopotamia to carry their household gods along with them wherever they traveled (cf. M. Greenberg in JBL 81:239–48—though this very late witness may be merely a deduction from Gen.)
Still unsolved is the problem of the nature of the teraphim in I Sam 19:11–17. It is scarcely possible that the word (used as a singular; cf. KJV, RSV, “image”) there refers to household deities, since archaeologists have found no such images that even begin to approach the size of a full-grown man (cf. W. F. Albright, Archaeology and the Religion of Israel, p. 114; cf. also Gen 31:34, where at least two teraphim could be hidden in a saddle). It has therefore been suggested that sometimes the word tĕrāpîm refers to an image in the shape of a head, bust, or cultic mask (cf. A. R. Johnson, The Cultic Prophet in Ancient Israel, p. 31, note 3), or, alternatively, that Michal’s teraphim were “old rags” (W. F. Albright, op.cit., p. 207, note 63). The size and even meaning and use of teraphim may have varied widely over the centuries.
Needless to say, teraphim were never condoned in the OT as legitimate appurtenances to the worship of the Lord; in fact, they came under frequent prophetic condemnation (I Sam 15:23; II Kgs 23:24; Zech 10:2).