R Convert list to lowercase

You should use lapply to lower case each character vector in your list

lapply(var1, tolower)

# [[1]]
# [1] "parts of a day"    "time in astronomy" "star"             
# 
# [[2]]
# [1] "tree tall" "pine tree"

otherwise tolower does as.character() on your entire list which is not what you want.

Use gsub

gsub("/", "", var1)
as.list(tolower(var1))

this will remove all your / out of your variable.