There are quite a few synonyms for the phrase "put your oar in." Some examples include "butt in," "meddle," "interfere," "intervene," "intrude," and "interject." All of these phrases essentially mean to involve oneself in a situation or conversation in which one is not necessarily invited or needed. Depending on the context, using any of these phrases can come across as either helpful or downright annoying. It's important to read the situation and understand when it's appropriate to speak up and when it's best to remain silent. Ultimately, the key is to communicate effectively without overstepping boundaries.