'amygdaloidal' originates from the Greek word 'amygdaloeidēs', where 'amygdalē' meant 'almond' and '-oeidēs' meant 'form or shape'.

'amygdaloeidēs' transformed into the Latin word 'amygdaloides', and eventually became the modern English word 'amygdaloidal'.

Initially, it meant 'almond-shaped', but over time it evolved into its current meaning of 'relating to or resembling an amygdaloid rock'.