The phrase "more first-string" refers to something or someone who is of greater importance, skill level, or value as compared to others. The antonym for "more first-string" could be "less important," "lower skilled," or "inferior." It implies that the subject or object is not as valued or desired as others. Another antonym for "more first-string" could be "second-string," "subordinate," "less prestigious," or "inferior." These antonyms suggest that the subject or object is not the first choice or top performer. Using antonyms can help make distinctions, expand vocabulary, and express ideas more accurately. Knowing antonyms can enhance communication and understanding in various contexts.