"see serng" meaning?

[kimmy]

hey again!

I was hearing a cantonese song and i heard the phrase "see serng" and I was wondering what it meant? thanks !!!

[Terence]

can't figure it out without context. Maybe
1. si1 soeng2 思想　think
2. si4 soeng4 時常　always
3. si4 soeng6 時尚　fashionable