(usu + to) to express approval of or give consent to (something), often in response to urging
She acceded to the suggestion of bouillon — Kate Chopin
(usu + to) to take up enter on (an office or position, esp the thronemonarchy)
accede to the throne
(usu + to) to become a party to (something, e.g. a treaty)
[Middle English acceden to approach, from Latin accedere to go to, be added, from ad- + cedere to go, cede]