- aint
- acquired immunodeficiency syndrome
- and how
- aneurysms
- anew
- angiosperms
- anglicize
- anglo
- anglophobe
- anopheles
- another cup of tea
- answer back to
- answer someone back
- answer the door
- anther
- anther lobe
- anthers
- anthocyanins
- anthropic
- anthropogenic
- anthropologist
- anthropology
- anti-grammatical
- aorta
- apart
- ape
- apex
- applicant
- application
- application form
- application software
- application window
- applies
- appointed time
- aptitude test
- aquifer
- aquiline
- arabia
- arabian sea
- arable
- archaeology
- archaic
- archbishop
- archbishopric
- archdeacon
- archer
- archetypal
- architectonic
- architectural
- architecture
- archive
- areal flood
- areca
- areola
- argon
- argosy
- argot
- arguably
- argument
- armadillo
- armored
- armorer
- armour
- arriviste
- arse over tit
- articulate
- articulated
- artificial insemination
- artistry
- as far as
- as much again
- as of
- as one man
- as opposed to
- as plain as the nose
- ascetic
- asphodel
- asr
- assessee
- assign
- assignation
- assured
- asterisk
- astir
- astis
- asvamedha sacrifice
- asylum
- at a blow
- azymous
- at bay
- at breakneck speed
- at fault
- at one's wits end
- at the eleventh hour
- at the helm
- at the mercy of
- at your leisure
- atavism
- atomy
- atone