'tell apart' definitions:

Definition of 'tell apart'

(from WordNet)
verb
Detect with the senses; "The fleeing convicts were picked out of the darkness by the watchful prison guards"; "I can't make out the faces in this photograph" [syn: spot, recognize, recognise, distinguish, discern, pick out, make out, tell apart]
verb
Mark as different; "We distinguish several kinds of maple" [syn: distinguish, separate, differentiate, secern, secernate, severalize, severalise, tell, tell apart]