'bootlicker' originates from the combination of 'boot' and 'licker', where 'boot' refers to footwear and 'licker' implies someone who licks, metaphorically indicating excessive flattery.

'bootlicker' evolved from the literal act of licking boots as a sign of submission or flattery, becoming a metaphorical term in modern English.

Initially, it meant 'someone who literally licks boots', but over time it evolved into its current meaning of 'someone who excessively flatters or is servile'.