Paronym

Paronyms are words that are pronounced or written in a similar way but which have different lexical meanings. Paronyms contrast with homonyms, which are words with different meaning having the same pronunciation or spelling. Examples of English paronyms include:
 * alternately and alternatively
 * collision and collusion
 * conjuncture and conjecture
 * eclipse and ellipse
 * excise and exercise
 * prolepsis and proslepsis
 * continuous and contiguous
 * affect and effect
 * upmost and utmost
 * deprecate and depreciate

The term paronym can also refer to words that are derived from the same root, i.e. cognate words.