"Complain of" is a commonly used phrase that expresses dissatisfaction or discontentment. However, there are several synonyms that can be used to convey the same meaning. Words like "grumble," "whine," "moan," "whinge," and "gripe" can all replace "complain of" in a sentence. For example, instead of saying "I complained of the long wait," one could say, "I grumbled about the long wait." Similarly, "She complained of the cold weather" could become "She whined about the cold weather." These synonyms all suggest a tone of dissatisfaction or annoyance, but the choice of which word to use will depend on the context and the speaker's tone.