11ac Usual US and Canadian name for a bowler hat.(5) 13ac gas comprising almost 80% of the Earth`s atmophere by volume,,osolated in 1772 by Scottish English chemist Daniel Rutherford.(8) (??t??g?n) 14ac Large pink-flowered water LKily regarded as sacred in India, China and Tibet, Nelumbo nucifera (5) 18ac Opening at the inner corner of the eye into which the lacrimalgland drains.(4-4) (????-?u?t) 20ac Medieval kingdom and former county (1974-96) of SW Wales, uniteed with Seisyllwg in the 10th century to form the larger kingdom of Deheubarth.(5)