(transitive) To add additional elements or components to (a framework, a concept, a device, etc.) in order to extend it.

Casually enjoying the nightlife of a town or city.

A vehicle designed to be driven principally on normal roads; an on-road vehicle

In one's thoughts, especially persistently or recurrently. / Causing worry or preoccupation.

simple past tense of go on

(informal) Used to indicate acceptance by the speaker of a proposal or challenge, especially a competitive one.

present participle of hinge on

(idiomatic) Facing a choice between two equally undesirable alternatives.

To depend on; to be contingent upon.

(baseball) Having reached a base in an inning. / Located within the premises of a military base. / (aviation) Flying the base leg of an approach.