Other forms: squeakily
If your voice is squeaky, it's high and a little shrill, like a cartoon character. If your shoes sound squeaky when you walk, you'll never be able to sneak up on someone.
It's hard for people to take you seriously if you always sound a little squeaky when you talk. Squishy, noise-making dog toys are squeaky, and so is Mickey Mouse's voice, as well as the rusty hinge on an old treasure chest. If something's squeaky clean, it's so immaculate that it squeaks a little — this phrase probably started in the 1970s in advertisements for dishwashing soap.