Na-adjective (keiyodoshi), Noun which may take the genitive case particle 'no', Taru adjective, Adverb taking the 'to' particle
calm and collected; with composure; having enough and to spare
Yojijukugo (four character compound)
彼は余裕綽々と落ち着いている。He seems to have much in reserve.
Also written 余裕しゃくしゃく【よゆうしゃくしゃく】、余裕綽綽【よゆうしゃくしゃく】