'irregularly-delivered' originates from the combination of 'irregularly' and 'delivered', where 'irregularly' is derived from Latin 'irregularis', meaning 'not regular', and 'delivered' from Old French 'delivrer', meaning 'to set free'.

'irregularly' changed from the Latin 'irregularis' to the Old French 'irregulier', and eventually became the modern English 'irregularly'. 'Delivered' evolved from the Old French 'delivrer' to the Middle English 'deliveren', and eventually became the modern English 'delivered'.

Initially, 'irregularly' meant 'not regular', and 'delivered' meant 'to set free'. Over time, 'irregularly-delivered' evolved to mean 'delivered in a manner that is not consistent or regular'.