Conversation

The word ‘sweet’ can be traced back to the Old English ‘swete’, an adjective that meant, ‘pleasing to the senses, mind or feelings’. Its origins are Proto-Indo-European (‘*swad’, Sanskrit svādu) which makes the word over 5000 years old.

'Sweet’ was used as a noun to mean ‘beloved one’ from 1300, as something easily managed from the 19thC , ‘the engine is more responsive and sweet than its predecessor’, and as an intensive from the 20thC , ‘sweet nothing’.

https://thecopy.team/blog/origin-word-sweet-copy-team-etymology-series/