*(g/k)wap

The present reconstruction is a revision of gop ⪤ kop, found in HPTB #11a. This revision seems to go better with the Baxter/Sagart reconstruction of the Chinese comparandum (see below).

This etymon, with velar stop or fricative initial reflexes, seems clearly to have an allofamic relationship to #2767 PTB *ʔup COVER / INCUBATE / HATCH. Other TB etyma showing variation between velar and zero (=glottal stop) initial include NEEDLE *kap (but WB ʔap), HOUSE *kyim (but WB ʔim), etc. See STC pp. 25-6, Matisoff 1997 (“Primary and secondary laryngeal initials in TB”), and HPTB p. 57.

This widely-attested root includes both simplex and causative allofams (thus the variation in voicing). It occurs in Tani, Himalayish, Jingpho, and perhaps Karenic. There is also a good Chinese comparandum, 蓋, meaning ‘cover; lid’ (below).

蓋 OC *gɑ̂p/*kɑ̂b>*kɑ̂d, GSR #642q, ‘to cover, thatch’ ⪤ ‘a cover, lid’; Li 1971: *gap/*kabh>*kadh; Baxter 1992 #1732, 1731: *ɦkap/*kaps>*kats; Mand. hé ⪤ gài.

These two related words perhaps derive from an unattested root *kap. The noun has an *-s suffix, which derives a passive noun from a transitive verb (i.e. ‘the thing that is used to cover’ > ‘a lid’). In the verb form, Baxter’s *ɦkap develops as *gap, the notation suggesting morphological derivation from a root with initial *k-. While voicing derivation is a well-known Old Chinese morphological process, it usually derives intransitives from transitive verbs, so the function here is not clear.

The only difficulty with the TB comparison is the vowel. While Baxter’s six-vowel system permits the possibility of reconstructing *ɦkop or *gop for the verb, the noun must be reconstructed with *a to account for subsequent sound changes, and this forces a reconstruction of *a in the verb as well.

It is possible that OC *a corresponds regularly to PTB *o before bilabial codas. Unfortunately, there are very few proposed cognate sets that would help us establish or refute such a possibility.
[ZJH]

盍 OC *g’ɑ̂p, GSR #642n-o ‘join, unite; door leaf’; Schuessler 2007:275 *gâp; B & S 2011: *m-kˁap {m-[k]ˁap}; Mand. hé.
蓋 OC *g’ɑ̂p; *kɑ̂b > *kɑ̂d; GSR #642q-r ‘thatch, cover (v.); cover, lid (n.)’; Schuessler 2007:275 *kâts < *kâps; B & S 2011: *kˁap-s {[k]ˁap-s}; Mand. gài.
閤 OC *kəp, GSR #675i ‘small gate’; Schuessler 2007:274 *kə̂p; B & S 2011: *kˁop {[k]ˁ[o]p}; Mand. gé.
蛤 OC *kəp, GSR #675h ‘oyster, mussel’; Schuessler 2007:274 *kə̂p; B & S 2011: (*kˁop); Mand. gé.
合 OC *g’əp, GSR #675a-d ‘join, unite; harmony; close, shut’; Schuessler 2007:274 *gə̂p; B & S 2011: *m-kˁop; Mand. hé.
洽 OC *g’ɛp, GSR #675m ‘unite, assemble; accord with’; Schuessler 2007:274 *grə̂p; B & S 2011: *ɢˁ‹r›op {[ɢ]ˁ‹r›[o]p}; Mand. qià.
翕 OC *χi̯əp, GSR #675q ‘united; harmonious’; Schuessler 2007:274 (*həp); B & S 2011: *qʰəp {qʰ(r)[ə]p}; Mand. xì.