All 6 Uses of

discreet
in
Me Before You

It was as I was passing reception that I saw the computer terminal, discreetly placed in a corner.†
p. 394.0 *

discreetly = in a manner that is unlikely to attract attention or cause embarrassment

I had been doing this for about ten minutes when the discreet hum of the motorized wheelchair alerted me to Will's arrival.†
p. 63.1

A warm sweetness rose from his skin, the scent of the shaving cream, and something that was peculiar to Will himself, discreet and expensive.†
p. 111.2

There were outside sunken baths with discreet hoists, and specialist masseurs.†
p. 309.8

The airline staff was solicitous and discreet, and careful with the chair.†
p. 344.9

Definitions:

(1) (discreet as in: discreet--not showy or gossipy)
trustworthy with secrets or subtle (not attracting attention)

This sense of discreet sometimes indicates that something is small (so as not to attract attention) as in "discreet earrings."
(2) (discreet as in: discreet--not foolish)
sensible and careful; possibly having good manners

This sense of discreet is more commonly seen in classic literature than in modern writing. There is may also refer to having the judgment to exercise good manners.