At full throttle is a phrase that refers to doing something with maximum effort or speed. The crossword solutions AMAIN (5 letters), LIU (3 letters), and DEMI (4 letters) are all related to this phrase. AMAIN is an archaic word meaning 'at full speed' or 'with full force'. LIU stands for 'Lift It Up', which is a phrase used to encourage someone to give their best effort. DEMI is short for 'demi-marathon', which is a long-distance running race that requires participants to push themselves to their limits.