Avakāsa & okāsa

1. “appearance”: akkhuddâvakāso dassanāya not little (or inferior) to behold (of appearance) DN.i.114; ariyāvakāsa appearing noble or having the app. of an Aryan Ja.v.87; katâvakāsa put into appearance Vv.22#9.
2. “opportunity”: kata˚ given leave DN.i.276; Snp.1030; anavakāsakārin not giving occasion Mil.383
   ■ anavakāsa not having a chance or opportunity (to happen), impossible; always in ster. phrase aṭṭhānaṃ etaṃ anavakāso Vin.ii.199; AN.i.26; AN.v.169; Pp.11, Pp.12; Pv-a.28.

ava + kāś to shine, cp. Sk. avakāśa