What is a better word for "squeaky"?

A better word for squeaky depends on context and what nuance you want, as squeaky has several meanings. If you mean high-pitched sound, better or more precise words include squealing, creaky, screechy, shrill, piercing, chirpy, or peepy. For example, instead of squeaky door, you could say creaky door if it is low-pitched or screechy door if loud. For voice, instead of squeaky voice, you could say high-pitched voice, shrill voice, tinny voice, or piping voice. If you mean morally clean as in squeaky clean, better words are spotless, immaculate, pristine, flawless, or unblemished. For example, squeaky clean record could be spotless record. If you mean complaining as in squeaky wheel, better words are complaining, vocal, demanding, or outspoken. For a toy, you could say squealing toy. So there is no single better word for all uses, but squealing is closest for sound, creaky for mechanical friction, shrill for annoying high pitch, and spotless for clean meaning. Choose based on whether you want to emphasize high pitch, friction, or cleanliness.