ad ‧ here /ədˈhɪə $ -ˈhɪr/ BrE AmE verb [intransitive] formal
[ Date: 1400-1500 ; Language: Latin ; Origin: adhaerere , from ad- 'to' + haerere 'to stick' ]
to stick firmly to something
adhere to
The eggs of these fish adhere to plant leaves.
adhere to something phrasal verb formal
to continue to behave according to a particular rule, agreement, or belief:
We adhere to the principles of equal rights and freedom of expression for all.
I have adhered strictly to the rules.