The word "lookin" is a slang term and is usually an abbreviation of "looking." Synonyms for this word include searching, observing, examining, and surveying. Other informal synonyms include peeping, peeking, gazing, and staring. These words can be used interchangeably depending on the context and intended meaning. For example, "searching" suggests a more thorough investigation compared to "observing," which implies a more casual glance. "Peeping" and "peeking" both suggest a secretive or furtive style of looking, while "surveying" implies a more systematic or organized approach. The choice of synonyms depends on the writer's style, tone, and purpose.