olfaciō

1. Odor and olere (ὄδωδα) denote, objectively, the smell which a thing has in itself, in opp. to sapor, etc., like ὀσμή; whereas olfactus and olfacere denote, subjectively, the sensation caused by this smell, or the sense of smell, in opp. to gustus, etc., like ὄσφρησις. 2. Olere means to smell, in opp. to being without smell, and especially denotes a rank and bad smell; whereas fragrare (from βρέχειν) denotes a good smell. Redolere and perolere are used as frequentatives; redolere denotes a strong smell in an indifferent sense; perolere, a penetrating smell, in a bad sense. 3. Olfactus is a smell, as far as it is an involuntary effect of the sense of smell; odoratus, as far as it is an intentional exertion of that sense. 4. Olfacere, to smell, is of a passive nature, like audire, the smell mounting up to the nose of itself; odorari, to smell at, to sniff, ῥίνηλατεῖν, is of an active nature, like auscultare, the man drawing up the smell into his nose of himself. Olfaciens sentit odorem, odorans captat. 5. Olidus denotes smelling, and particularly with a bad smell; odorus, with a good smell. Hence, bene olidus denotes merely the negative of a stench; odorus, a positive good smell; and the antiquated word olor denoted a stench, like oletum; but odor denotes only a smell. (iii. 131.)