'irregularly-grown' originates from the combination of 'irregularly' and 'grown', where 'irregularly' is derived from 'irregular', meaning 'not regular', and 'grown' is the past participle of 'grow', meaning 'to increase in size'.

'irregularly' changed from the Middle English word 'irreguler', and 'grown' from the Old English 'grōwan', eventually forming the modern English term 'irregularly-grown'.

Initially, 'irregularly' meant 'not following a pattern', and 'grown' meant 'having increased in size', which together describe something that has increased in size without a regular pattern.