Lambaste

The verb 'to lambaste' is recorded with two spellings, with or without a final silent '-e-'. These are reflected in two separate pronunciations, of which AWE recommends the one with a 'silent -e'. This better represents the probable etymology, which OED gives as 'to baste', 'to beat soundly', 'to thrash' - a colloquial term first used in the sixteenth century.

• Lambaste with the silent -e should be pronounced regularly to rhyme with 'taste' and 'waste' - IPA: /læm 'beɪst/. This is AWE's recommendation.
• The less etymological lambast may be the cause of the pronunciation frequently heard these days, to rhyme with 'gassed' and 'massed': IPA: /læm 'bæst/.