#atravesar# pass through
#atreverse# dare
#atroz# atrocious, fierce
#aumentar# increase
#aumento# increase
#aun, aún# still, even, yet; #— no# not yet
#aunque# although, even though
#ausencia# absence
#ausentarse# depart, go away, be absent; #al —# in the absence of
#ausente# absent; absent one