Terms in an algebraic expression which are the same in relation to all variables and their powers and which are separated by addition or subtraction signs. Like terms can then be combined into a single term. So in 3x²y + 6xy−5xy²−2xy there are two like terms, the terms involving xy, but the other two terms are not ‘like terms’. This expression could be simplified to 3x²y + 4xy−5xy² but no further.