If you lived in the starched pinafore and perfect updos 1950s, a "Gal" is a woman. If you survived the early swinging 1960s with Frank Sinatra (or without him for that matter, there was only so much of him to go around after all), then a "Gal" was just some hip chick who was cool enough to be seen with for brief periods of time before the call of a decent surf or a cold beer returned the "Guy" to his senses.
The term is rooted firmly (to the point where it is sprouting leaves) in the British language. In this archaic form of English (since overtaken by modernspeak "American English", girls were first called gulls. On the useful scale of how the old bird ages, the following progression is extremely evident to anyone who bothers to delve more deeply into the development of language:
- Gulls mature to chicks
- Chicks mature to birds
- Birds mutate into gulls at around 35 when they lose their
looksability to be taken in by the hawks -> eagles -> mutton birds.
Yeah, go figure. It doesn't even make sense on the 5 word meaning change puzzle but what the heck.
On Using Gal
Today, if you are a man and call an woman a Gal, you stand a very good chance at being bitch slapped into eternity.
However, one woman can call another woman/women Gal/Gals and get away with it because it's cute in the way that right shade of red in sling back heel is cute. Not, "OH MY GOD, where did you get those shoes!" but simply "Those shoes are really cute!"
Women who have matured into a life of middle-class tedium may also call one and other in a calm but friendly tone of voice "Hey Lady!", again because they think it's cute; but it isn't. Its cheap and affected. The only women who are entitled to use the phrase "Hey Lady! are white trash women who have won a free trip to England by submitting contest forms, and even then use the word sparringly when approaching British royalty at Ascot. (The only man who can use (shriek) the term "Hey Lady!" is that genius of comedy, Jerry Lewis.)