The phrase "lend one aid" means to help or assist someone in need. Synonyms of this phrase include "provide assistance," "offer support," "give a hand," "extend help," "grant aid," and "render assistance." Other related words could include "aid," "helping hand," "support," "guide," "mentor," "protect," "serve," "abet," "bolster," "boost," "back up," "champion," and "encourage." It is important to offer aid and assistance to those who need it, and having a variety of vocabulary options can help you communicate clearly and effectively in these situations.