To raise to the same level or status; to improve so as to make as good as others.
To progress to the next level of player character stats and abilities, often by acquiring experience points in role-playing games.
To augment; to improve; to intensify.
To make strong or stronger; to add strength to; to increase the strength of; to fortify.
To empower; to give moral strength to; to encourage; to enhearten.
To reinforce, to add to, to support (someone or something)
To grow strong or stronger.
To substantiate; to corroborate (a belief, argument, etc.)