An improvement. / (law) An improvement to a property that adds to its value.

plural of betterment

continually improving

comparative degree of good / comparative degree of well / Greater in amount or quantity

comparative degree of well / Greater or lesser (whichever is seen as more advantageous), in reference to value, distance, time, etc. / (colloquial shortening) Had better.

An entity, usually animate, deemed superior to another; one who has a claim to precedence; a superior.

(modal, auxiliary verb, colloquial) Had better.

(transitive) To improve. / (intransitive) To become better; to improve. / (transitive) To surpass in excellence; to exceed; to excel.

Alternative spelling of bettor

simple past tense and past participle of better