The Collaborative International Dictionary of English v.0.48:
Trainable \Train"a*ble\, a.
Capable of being trained or educated; as, boys trainable to
virtue. --Richardson.
[1913 Webster]
Moby Thesaurus II by Grady Ward, 1.0:
38 Moby Thesaurus words for "trainable":
aimable, aimed, apt, bright, clever, directed, directional,
directive, dirigible, docile, educable, facile, formable, guidable,
impressionable, instructable, intelligent, leadable, malleable,
moldable, motivated, on the mark, on the nose, plastic, pliable,
pointable, quick, ready, receptive, ripe for instruction,
schoolable, steerable, susceptible, teachable,
thirsty for knowledge, well-aimed, well-directed, willing