Designate, name, nominate, elect, appoint are comparable in the sense to declare a person one’s choice for incumbency of an office, position, post, or benefice.
Designate implies selection by the person or body having the power to choose an incumbent or to detail a person to a certain post; it often connotes selection well in advance of incumbency.
Name varies little in meaning from designate except that it stresses announcement rather than selection; it is more informal, however, and is usually preferred when the reference is to a political or government office within the gift of an executive or of an executive body.
Nominate, though etymologically the equivalent of name, is rarely used as its equivalent in meaning.
Usually it implies merely the presentation of the name of one’s choice for an office for approval or rejection by others who have the final say; thus, a person from the floor at a convention may nominate his choice for a particular office; a state convention of a political party meets to nominate the party’s candidates for governor and other state officers.
Either nominate or name may be used when the executive’s choice must be confirmed by a body having that power.
Elect, as distinguished from nominate, implies a final selection (as by the electorate) from the candidates who have been previously nominated.
Appoint always implies that the selection is determined without a general vote (as of an electorate) and represents the choice of the person or the body in whom such power is legally vested.
Appoint may be used even when confirmation (as by the U. S. Senate) has been necessary to make the designation valid.