That word doesn´t exist.... where did you read it?

I think you got the word wrong... it doesn't sound like anything i can recognize! Unless you mean 'estando', then it means 'being', as a 'to be' conjugation

testar 1 intr. Hacer testamento: sus padres murieron sin testar. testar 2 tr. Someter a test a una persona o cosa para comprobar sus conocimientos o sus propiedades y calidad: testamos todos los productos en nuestro laboratorio. Testando es el gerundio Tiempo verbal) del verbo testar: to make one's will No se me ocurre otra cosa. Esa palabra (lestando) no existe en español. También podría ser "listado".

there have been a couple times when ive seen people write " 'lestando " as a shorter version of the verb " molestar " which means " to bother ". that being siad "lestando" may refer to "bothering". its a long shot, but thats all i can think of. best of luck!