Lawyers for the Justice Department and the Federal Communications Commission disagreed in the Supreme Court yesterday about whether words that crudely depict sexual organs and excretory functions can be barred from the airwaves day and night.

For the department, Louis F. Claiborne argued that the FCC could prohibit such words - "indecent" but not pornographic or obscene - from broadcasts specifically aimed at children, no matter what time they are carried.

But to outlaw them regardless of the context in which they are used, for all or most of the broadcast day, violates the First Amendment guarantees of free speech, Claiborne contended.

For the fee, Joseph A. Marino argued that a 1927 law requires the agency to order that sexual and excretory words not be broadcast during hours when there is a reasonable risk that children may be listening. The law prohibits broadcast of "indecent" language while also prohibiting censorship of program content.

The commission has intimated that its order is conditionally lifted after 10 p.m. Clairborne said that this qualification by the FCC still cannot be squared with freedom of speech, partly because many juveniles - with or without parental consent - play radios after that hour, and partly because the order censors radio for adults who listen to it only in the daytime or evening.

The broadcast at issue occurred at about 2 p.m. on Oct. 30, 1973, on WBAI-FM, a New York City noncommercial, listener-supported station operated by the Pacifica Foundation.

As part of "a general discussion of the use of language in our society" and after a warning that listeners might want to switch stations for 15 minutes because some words would be spoken that might offend them, the host played a recording of a monologue by satirist George Carlin.

In the record, entitled "Filthy Words," Carlin used seven words, running from three to 12 letters each, that, he said, "you couldn't say on the public . . . airwaves . . . "

The words also were not spoken in the Supreme Court chamber. When argument began late Tuesday, Chief Justice Warren E. Burger said pointedly that the court was "fully aware" of the facts.

One radio listener, described only as a man who said he was tuned to WBAI while driving with his young son, complained to the FCC.

Justice Thurgood Marshall, noting there had been only "one program, one recording, one man, one son, one complaint," wondered if the man spoke for "the community."

"He certainly did," Marino replied.

"What makes you think that?" Marshall asked.

The man could purport to speak for the community in terms of raising a question that the FCC was obliged to look into, Marino replied.

Burger interjected that official action can be triggered by a single citizen, who, say, reports a fire.

"This wasn't a fire," Marshall shot back.

The FCC responded to the complaint in February 1975 by declaring the seven words - "deliberately broadcast" and "repeated over and over" - to be "indecent" within the meaning of the law. It emphasized that the words were aired when "children were undoubtedly in the audience."

The commission ordered an absolute ban on use of such words by any broadcaster at any time when children - undefined as to age - might be listening. The Justice Department says that along with adults, children are listening "at all times."

The Pacifica Foundation appealed. The U.S. Court of Appeals for the District of Columbia in a 2 to 1 decision, held that the order violated the First Amendment.

"is it the position of the Department of Justice that anything goes?" Burger asked Clairborne.

No, replied the assistant to the solicitor general. Not, for example if words such as those in the Carlin record are used "in a hostile manner so as to insult the audience generally or anyone in particular." The judgement must be made in the context of how such words are used, he said.

Under communications law, a broadcaster carries the burden of showing that renewal of his license would serve the public interest.

Suppose, the chief justice said, that a station had done exactly what WBAI had done, and was accused by a coalition of church, P.T.A. and civic groups of having performed in a way antagonistic to the public interest. What then?

Clairborne replied that the commission would be obligated to focus not "on an isolated instance," but on whether the station devoted "a very substantial part of its programming" to material that offended its audience.