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ETYM French apte, Latin aptus, from obsolete apere to fasten, to join, to fit, akin to apisci to reach, attain: cf. Skr. âpta fit, from âp to reach attain.
1. Mentally quick and resourceful; SYN. clever.
2. (Usually followed by 'to') Naturally disposed toward; SYN. disposed, given, minded, tending.
3. At risk of or subject to experiencing something usually unpleasant; SYN. liable.