to stand straight; to stand erect; to stand upright

erect; upright

let something grow long / straighten out / expand, extend, increase / spread

(anatomy) either the spine, or the middle groove of the back along the spine / (clothing) the middle seam of the back

(anatomy) a back muscle

he / distal demonstrative, something far off removed from both speaker and listener: that / boyfriend

distal demonstrative, something far off removed from both speaker and listener: that, yon / particularly, male personal third person pronoun: he / by extension from he: boyfriend

he; boyfriend

to stretch one's legs out / (figuratively) to reach one's destination and then proceed to go further

(idiomatic) to let your hair down; to have fun after a period of work or stress