The origin is uncertain. Cf. perhaps Arb. ˁqr (V) ‘to be accumulated (fat on an animal); to grow well (plants)’, Tna. ˁaḳärä ‘to save, to put in reserve; to hoard, to amass, to accumulate’, Amh. aḳḳwärä ‘to collect’. (Kogan 2015:548-549) also a verbal noun traceable to Proto-MSA: *ˁaḳar- ‘growth’, cf. Mhr. ˀāḳər ‘size’ (ML 20), Jib. ˁáḳər ‘size’ (JL 11), Soq. ˁáḳar ‘size, age’ (LS 325).
di-ˁö́ḳar ‘big’:
ḳö́ṣafk ẓ̂áˀed di-ˁeḳároʰ ‘I felled a big Ziziphus tree’ (CSOL I 9:5)
di-ˁö́ḳar ‘elder’:
gédaḥ ˁouyέghɛn deʰ di-ˁö́ḳar ‘The elder boy came’ (CSOL I 6:38)
nafs di-ˁeḳároʰ ‘greedy soul’ (Bulakh 2024:176)