The antonyms for the phrase "sticks neck out" include terms such as being cautious, reserved, and taking a back seat. In essence, these antonyms denote a sense of reluctance to take risks or make bold moves. Words like "play it safe," "hold back," and "stay in line" all describe a mindset that prioritizes safety and conformity over daring innovation. Taking risks can be intimidating, but not doing so can be equally unsatisfying. In life, balance is key, so while caution can be wise, having the courage to take chances can lead to great rewards.