flat, even, level, smooth, having no variation in altitude / stable, calm, at peace / relaxed, lacking formality

a title (name of a book, etc) / (publishing) a title (publication) / (sports) a title (recognition given to the winner of a championship in sports)

approximately

excellent plan / outline

retreat

to retreat

(accounting) credit and debit, lending and borrowing

notice of withdrawal

tackle, body blow, body check

body check, tackle / give all one's might, give everything you've got