Citation 1: [L=238711] sarvavid f. the sacred syllable Om L.

Firstly, the gender appears to be suspicious. Most names for monosyllable Om that I have come across are either masculine (praṇavaḥ, oṃkāraḥ, udgīthaḥ, etc.) or neuter (ekākṣaram, brahmākṣaram, etc).

Anyway, my question is that which lexicon (the abbreviation L.= Lexicographers, esp. such as अमरसिंह, हलायुध, हेमचन्द्र, &c.) gives the meaning of Om for the word ‘sarvavid’?

Citation 2: [L=175517] rasa N. of the sacred syllable, “Om,” S3a1n3khGr2.

Where in शाङ्खायन-गृह्य-सूत्र is the word ‘rasa’ used for Om? I searched in the digital version of Bloomfield’s Concordance but did not find it.