superficial
shallow, lacking in depth
superfluous
extra, more than enough, redundant
suppress
to end an activity
surreptitious
secret, stealthy
tactful
considerate, skillful in acting to avoid offense to others
tenacious
determined, keeping a firm grip on
transient
temporary, short-lived, fleeting
venerable
respected because of age
vindicate
to clear from blame
wary
careful, cautious