maximum

(noun) the largest possible quantity. Synonyms: upper limit.

(noun) the greatest possible degree. Synonyms: utmost, uttermost, level best. Examples: "He tried his utmost."

(noun) the point on a curve where the tangent changes from positive on the left to negative on the right.

(adj) the greatest or most complete or best possible. Synonyms: maximal (vs. minimal), maximum (vs. minimum). Examples: "Maximal expansion." "Maximum pressure."