om=old man    of=old friend
韦氏大学词典     
old man  
function:           noun 
date:               1673 
1 a : husband b : father 
2 capitalized : one in authority especially : commanding officer 
3 : boyfriend especially : one with whom a woman cohabits
朗文当代英语词典     
old man  
.old 'man
n [c] 
 1.old-fashioned informal someone's husband, father, or boyfriend
 i heard her old man beats her.
 2.bre old-fashioned used when speaking to a male friend
 could i have a word with you, old man?
剑桥高级学习词典     
old man  
old man noun [s] slang
someone's father or someone's husband:
柯林斯高级英语学习词典第5版     
old man
[n-sing] the/poss n
some people refer to their father, husband, or boyfriend as their old man. (informal)
维科英汉词典     
old man  
老头子; 情人; 丈夫; 父亲