Is a topcoat the same as an overcoat?

Topcoat and overcoat can be same in fashion context but different in painting context. In fashion and clothing, topcoat and overcoat are essentially same, both refer to long outer coat worn over suit or clothing in cold weather, terms used interchangeably, though traditionally topcoat is lighter weight and shorter than overcoat which is heavier and longer for very cold, but modern usage they are same, meaning outer coat. For example, wool topcoat and wool overcoat both mean long coat. In painting and finishing, topcoat and overcoat are not same, topcoat is final finishing coat that provides color, sheen, and protection, overcoat can mean any coat applied over another coat, which could be second coat of paint, not necessarily final. For example, in house painting, topcoat is final color coat, overcoat could be second coat over first. In automotive, topcoat often means color plus clear, overcoat could mean clear over color. So in clothing, topcoat and overcoat are same, both outer coats, slight difference in weight, but in painting, topcoat is specific final coat, overcoat is general term for any coat over another. So answer depends on context, fashion they are same, painting they are related but not identical.