【Deviation】 , 【aberration】 , 【divergence】 , 【deflection】 denote departure or an instance of departure from a straight course or procedure or from a norm or standard.

【Deviation】 , the term of widest application, usually requires qualification or a context to complete its meaning.

【Aberration】 adds to  【deviation】 definite implications of error, fault, or abnormality and therefore has highly technical significations in some of the sciences. In general use it commonly implies transgression of the moral law or the social code and is often used euphemistically for a reprehensible act or reprehensible behavior.

【Divergence】 is sometimes used interchangeably with 【deviation】 , but ordinarily it denotes 【deviation】  of two or more things which from a common starting point proceed in different directions.

【Deflection】 adds to 【deviation】 the implication of bending or curving.