2234: A greater measure
One unclued light is the name of a drink which can be measured into three ingredients. Each ingredient has three definitions among the other unclued lights; unchecked letters of the nine lights in question are supplied by the puzzle’s title. Across 1 Changing tack, see, I perform on rink? (8, hyphened) 8 Total power in reservoir (4) 12 Contemptuous expression in silence covered by hand (5) 14 Commend arrangement of test run (7) 16 Corridor without a key?