Long Vowel Rule (1): When a word has two vowel, usually the first vowel says its name and the second vowel is silent.
gill noun (FISH) âº [ 1  C usually plural ] the organ through which fish and other water creatures breathe. âº 2  us â [ C ] a measure of liquid that is equal to 0.142 litres or a quarter of a pint. âº 3  the organ through which fish and other water creatures breathe.
Medical Definition of gill. : either of two units of capacity:a: a British unit equal to 1â4 imperial pint or 8.669 cubic inchesb: a United States liquid unit equal to 1â4 United States liquid pint or 7.218 cubic inches.