COMMITMENTS : OK, It’s a Guy Thing--but What Does <i> That</i> Mean? : Language: This catchy, convenient phrase has several hidden meanings. You’d think men could explain, but sometimes, even they are at a loss for words.

A man spits, or watches 11 hours of football, or howls as he and his buddies re-enact last night’s episode of “Beavis and Butt-head.”

The meaning of such behavior has puzzled women (and more than a few men) through the ages, but finally we have an answer:

It’s a guy thing.

OK, but just one question. What does that mean? “It’s a guy thing” may be a popular description of stereotypical male behavior, but that doesn’t mean it can be easily defined--perhaps because it’s not supposed to be.

The phrase exists mainly so men don’t have to explain why they do the things they do, and so women can avoid having to consider the nasty particulars.

Translation: It’s a guy thing--you wouldn’t want to understand.

Or maybe the difficulty of defining this throwaway line is that men haven’t given a whole lot of thought to their macho eccentricities, introspection not being at the top of the list of guy things.

As in: It’s a guy thing. Even I don’t understand.

Well, then, who does? Believe it or not, a lot of really smart people have given this phrase--and its relation to understanding between the genders--a lot of thought. Their thoughts range from theories of men redefining themselves in a post-feminist world to sheer amazement at the prodigious levels of male saliva output.

“Men, for no reason at all, seem to spit a lot. All I can say, besides ‘Gross!’ is, ‘Hey, it’s a guy thing,’ ” said Amy Guy (no relation) of Kenyon College in Gambier, Ohio.

At the heart of the phrase is the notion that certain activities, by nature or nurture, are particular to one sex, and perhaps not very well understood by the other. That may explain why you rarely hear the words shopping and belching in the same sentence.

There is at least one known fact: The meaning of “It’s a guy thing” is in the mind of the beholder.

Men sometimes say it to women to try to explain the unexplainable. Any attempt to break it down any further would defeat its purpose. After all, nobody ever asks the French to explain “ C’est la vie .”

It also may serve as an explanation for why men like to watch Monday Night Football together, in terms of a need for male bonding, said James Bracy, a social psychologist at Cal State Northridge.

When women use the phrase, they may truly be curious, searching for the Rosetta Stone of male behavior and hoping not to come up with the same old tabula rasa.

Or, in another interpretation, women may just want to mock male behavior, Guy said.

Chuck Kleinhans, an associate professor of radio, television and film at Northwestern University in Evanston, Ill., said, “When men use ‘It’s a guy thing,’ it means ‘Don’t bother me about this,’ or ‘You wouldn’t understand.’ When you hear a woman say it, it’s to put down men.”

An inability by men to articulate their “guyhood” to women may have something to do with the alleged male penchant for doing rather than saying, said Paul Somerville, who also claims to be the founder of the Department of Manliness at Morningside College in Sioux City, Iowa. As an example, he cites a line by John Wayne, an archetypal guy’s guy, from the movie “The Undefeated.”

Woman: “You said you were going to talk to him, and you ended up killing him. Why?”

Wayne: “I guess the conversation just sorta dried up, ma’am.”

So much for historical antecedents.

But why did this phrase come about now? The news, as usual, may not be good, fellas. It’s another one of those the-dominant-male- going-the-way-of-the-dinosaurs deals, some theorists say.

Before feminism, men usually didn’t have to try to explain their behavior--their efforts to be the strongest, the toughest, the funniest, said Joe Urgo, associate professor of English and humanities at Bryant College in Smithfield, R.I. Male behavior was interpreted as human behavior.

But not anymore.

Thus, the catch phrase can be viewed as a welcome male self-consciousness, “a reassertion of the right to be a male heterosexual in an era that questions the primacy of that categorization,” Urgo said. (Not that there aren’t women and gay men who enjoy the manly arts of belching, hunting, designing tall buildings or starting wars.)

Or, said Marshall Fishwick, a professor of communication studies at Virginia Tech in Blacksburg: “It seems that ‘the boys’ want to reclaim some of their uniqueness that they gave up when ‘girls’ began to play baseball, become lawyers and fly F-14s.”

Somerville ultimately defines the phrase in terms of what it isn’t.

“This is what a guy thing is, when all is said and done: A thing that guys can do that women can’t (of which there is a decreasing number), don’t (of which there is a slightly larger number) or won’t (of which there is a rapidly increasing number) do,” he concluded.

Make any sense? If so, great. If not, well, you know. It’s a guy thing.