| Term | Definition |
| a- | no, not, without, away from |
| ab- | away from |
| abdomin- | abdomen |
| ablat/o | to remove, to destroy |
| abrad/o | to scrape, to wear away |
| -ac | pertaining to |
| acanth/o | thorny, sharp spine |
| acar/o | mites |
| acid/o | acid, sour, bitter |
| acou- | hear |
| acr/o | extremities, top |
| act- | drive, do, act |
| actin/o | radiation, ray |
| acu- | needle |
| -ad | toward, in the direction of |
| ad- | toward, increase |
| aden/o | gland |
| adenoid/o | adenoids |
| adip/o | fat |
| adren/o | adrenal glands |
| aer- | air |
| agglutin/o | clumping |
| agit/o | rapidity, restlessness |
| -agogue | simulator, agent causing change |
| -agra | severe pain |
| -al | relating to |
| albin/o | white, deficient pigmentation |
| -algesia | pain |
| -algia | pain |
| aliment/o | nutrition |
| allo- | other |
| alve- | channel, cavity |
| alveol/o | alveolus |
| ambi- | both, both sides, around |
| ambly/o | dull, dim |
| ambul/o | walking |
| amni/o | amnion, sac around embryo |
| amphi- | both sides |
| ampho- | both sides, double |
| amyl- | starch |
| -an | pertaining to |
| an- | not, without, away from |
| an/o | anus, ring |
| ana- | up, apart, again |
| andr/o | male |
| andro- | male |
| angi/o | blood or lymph vessel |
| anis- | unequal |
| ankyl/o | bent, stiff |
| anomal/o | irregular |
| ante- | forward, before |
| anter/o | front |
| anthrac/o | carbon, coal |
| anthrop/o | human life |
| anti- | against |
| antr/o | antrum, cavity |
| aort/o | aorta |
| -apheresis | separation, removal |
| aphth/o | ulcer |
| apic/o | apex |
| apo- | separate, away from |
| append/o | appendix |
| aque/o | water |
| -ar | pertaining to |
| arch- | beginning, origin, first |
| arteri/o | artery |
| arteriol/o | small artery |
| arthr/o | joint |
| articul/o | joint |
| -ary | pertaining to |
| -ase | enzyme |
| aspir/o | inhaling |
| asthen- | weakness |
| astr/o | star |
| atelo- | incomplete, imperfect |
| ather/o | plaque, soft fatty deposit |
| atmo | steam, vapor |
| -atresia | closure, occlusion |
| atreto- | closed |
| atri/o | atrium |
| audi/o | hearing |
| aur/o | ear |
| auto- | self, same |
| aux/o | growth |
| axi/o | axis |
| axill/o | armpit |
| azot/o | nitrogen |