Of a quality, state of things, activity, wealth, etc.: To become gradually greater or more striking; to increase in potency or intensity.

intransitive. To become stronger, be reinforced.

intransitive. To become stronger or more intense; to increase in strength to a certain point; spec. (of the colour in a person's face) to become…

intransitive. To gain strength, grow strong. Obsolete.

intransitive. To become strong or stronger; to grow in strength or intensity.

Of a (usually immaterial) thing. Frequently with into. intransitive. To become more severe, harsh, or rigorous; to develop into something…

intransitive. To become more intense. Obsolete.

intransitive. figurative. To become more complex or intricate (esp. said of a plot); to increase in intensity.

intransitive. Of a disease, etc.: To increase in violence or severity. Cf. sense 2. Obsolete.

intransitive. To become intense, to grow in intensity.

intransitive. To become thick, in various senses; = thicken, v. Now dialect or archaic.

intransitive. Of an activity: to become more intense. Also: (of an adverse situation) to become increasingly difficult or uncomfortable.

figurative. to build up. transitive and intransitive. Of an electric current, volume of sound, etc.: to increase.