El Vestido
why does the word for a dress in spanish, i.e. el vestido have a masculine ending?
2 Answers
The gender of the word has nothing to do with who wears it (in the case of vestido) or whom it refers to. Una rana (macho o hembra). Una jirafa (macho o hembra). Una hormiga, etc. You also have Greek derived words like un estadista, un economista, un especialista, which are invariable in the feminine: una estadista, una economista, una especialista.
There is no simple or logical answer to your question--but, perhaps it comes from the general term of "apparel" rather than the specific term/noun of "dress" meaning a clothing item with a "skirt"! There are many words (nouns) in Spanish that one would think should be either masculine or feminine, but aren't! There are also many words (nouns) in Spanish that end in the letter "a", which would normally indicate a feminine gender, that are actually masculine and many that end in the letter "o", which would normally indicate a masculine gender, that are actually feminine! Some examples:
la mano = hand
la radio = radio
el problema =problem
el mapa = map
el día = day
The book, "1001 Pitfalls in Spanish", is an excellent reference for many of these types of questions.