awk partly string match (if column/word partly matches)

Question

My dummy file looks like this:

C1    C2    C3    
1     a     snow   
2     b     snowman 
snow     c     sowman

I want to get line if ther

Answer 1

GNU sed

sed '/\s*\(\S\+\s\+\)\{2\}\bsnow\(man\)\?\b/!d' file

Input:

C1    C2    C3    
1     a     snow   
2     b     snowman 
snow     c     sowman
      snow     snow     snowmanx

..output:

1     a     snow
2     b     snowman