WordNet sense 1 (detect with the senses):

discern, recognize, recognise, make out, pick out, tell apart

WordNet sense 2 (make conspicuous or noteworthy):

signalize, signalise

WordNet sense 3 (identify as in botany or biology, for example):

describe, discover, identify, key, name, key out

WordNet sense 4 (be a distinctive feature, attribute, or trait; sometimes in a very positive sense):

differentiate, mark

WordNet sense 5 (mark as different):

separate, tell, secern, secernate, severalise, severalize, separate