Yes it is a verb as well!
It could mean the following :
- to give medical treatment to
- to prescribe for a disease or disorder
- informally ( as an intransitive verb) it could mean to practice medicine.
"He doctored in India for 2 years."
Other informal meanings:
- to repair or mend ,specially in a makeshift manner, restoring by replacing a part or putting together what is torn or broken.
- to make different ( alter ) in order to deceive, falsify, tamper with or adulterate:
"He was suspected to have doctored the election returns."
- modify or adjust for a desired end by alteration or special treatment.
" The director doctored the play to suit the audience. "
- to adapt for a desired end ,effect etc..
- to castrate ( a cat or a dog etc)