Like a leech refers to something or someone that clings on tightly, draining resources or energy. There are many synonyms for this phrase that convey the idea of being a burden or a nuisance. These synonyms include phrases such as "like a parasite," "like a sponge," and "like a pest." Other possible synonyms include "like a bloodsucker," "like a freeloader," and "like an opportunist." Each of these phrases suggests someone or something that takes from others without giving much back in return, often causing frustration or annoyance. All of these phrases reflect the negative connotations associated with being a leech.