The Republican gubernatorial nominee apologized today for an off-the-cuff remark suggesting that some victims of rape should ''relax and enjoy it.''

The candidate, Clayton Williams, had initially played down the remark as being a joke.

Women's groups and political opponents of Mr. Williams strongly criticized the candidate for the comment.

It ''questions his ability to understand the kinds of problems faced by the people of Texas,'' said Ann Richards, the State Treasurer and a runoff candidate for the Democratic gubernatorial nomination. ''Rape is a crime of violence.''

Mr. Williams made the remark on Saturday while preparing for a cattle roundup at his West Texas ranch. He compared the cold, foggy weather spoiling the event to a rape, telling ranch hands, campaign workers and reporters around a campfire, ''If it's inevitable, just relax and enjoy it.''