Peripheral

- relating to or situated on the edge or periphery of something.[pɪˈrɪf(ə)r(ə)l]

Core[when it's adj]

- central to the existence or character of someone or something.[kɔː]

Shallow work

- low-energy task

Tackle[v.]

- make determined efforts to deal with (a problem or difficult task). [ˈtakl]

Impetus[ˈɪmpɪtəs, n.]

- the force or energy with which a body moves.

prioritize

- [prʌɪˈɒrɪtʌɪz] - designate or treat (something) as being very or most important.

suppress[səˈprɛs]

- forcibly put an end to.