The Idiom Attic - a collection of hundreds of English idioms, each one explained.
The meaning of "that sucks"
" That sucks "
Meaning:
1. An expression of sympathy. 2. Said of something that the speaker rates very lowly.
Example:
1. I heard that your child has leukaemia. That sucks - I'm so sorry. 2. His singing is out of tune and he just can't dance. The whole performance sucks.