There are several alternatives that can be used instead of saying "drop an idea." One option is to say "suggest" or "propose," which means to put forward an idea for consideration. Alternatively, one could use "present" or "offer" to indicate the act of suggesting a concept or proposal. "Introduce" or "bring up" are also frequently used to convey the idea of initiating a conversation or discussion around an idea. Finally, "mention" or "allude to" can be used when referring to a casual or passing comment about a potential concept or plan. Each of these options is a useful way to express the act of suggesting an idea.