- ask for the moon
- asokatree
- asphyxia
- asphyxiate
- asphyxiator
- aspiration
- aspire
- assassinate
- assassination
- assay
- assembling
- assertion
- assessment year
- asset
- assignee
- assimilate
- associated
- association
- assumed
- assurance
- assure
- asterism
- astigmatism
- astonishment
- astral body
- astraphobia
- astro
- astrobotany
- astrodome
- astrologer
- astron
- asymptote
- at all costs
- at every turn recurrently
- at issue
- at large
- at odds in
- at one time previously
- at peak
- at random
- at school
- at sea
- at someone's disposal
- at someone's disposition
- at stake
- at the end of
- at this rate
- at times sometimes
- atelophobia
- athiest
- athlete
- athletic exercise
- athletics
- atomic
- atomic number
- atomic theory
- atrophy
- attachment
- attack
- attagirl
- attained puberty
- attainment
- attempt
- attendance register
- attention
- attire
- attractive
- attributable
- attribute
- atwitter
- au courant
- audibility
- audible
- audibleness
- audience hall
- audio-visual aids
- audiometer
- augean
- augur
- auld lang syne
- auricular
- auspicious function
- autodidact
- auspicious woman
- austere
- authentically
- authoress
- authorial
- authorization
- authorize
- authorship
- autistic
- autobiography
- autogenously
- autolysis
- automatic check
- autonomous
- auxiliary
- auxiliary bishop
- avail