My Korean-English dictionary defines 축내다 as "spend (a certain amount, part of a sum)" and gives the following example sentence:
1,000원에서 100원을 축내다.
Spend 100 won of the 1,000 won.Am I the only one who finds the above definition somewhat confusing? Why is it confusing? Because every time someone spends, he or she spends a certain amount, so why bother putting "a certain amount" in parentheses? And what does "spend part of a sum" mean? That someone spends part of his or her money? Duh! Again, isn't it obvious that when someone spends, he or she will be spending part of or all of a sum of money, so why put it in parentheses?
My Korean-English dictionary defines 축나다 as "decrease; run low; lack; be deficit; fall (become) short of" and gives the following example sentence:
돈이 500원 축난다.
There is a deficit (shortage) of 500 won.So, according to the example sentence, 축(縮) means deficit. In fact, my Korean-Korean dictionary says 축 is an abbreviation of 흠축(欠縮), which my Korean-English dictionary defines as "shortage; deficiency; want; deficit; lack." Therefore, since 내다 is the causative of 나다, the word 축내다 literally means "to cause a deficit." In other words, when you spend more money than you have, you run a deficit and, thereby, accumulate debt. However, in the first example sentence above, 축내다 seems to have been used with a different meaning.
Notice that one of the meanings of 축나다 is "decease," which means 축내다 could also be interpreted as "to cause a decease." Therefore, the first example sentence (1,000원에서 100원을 추내다) seems to be referring to someone who spent 100 won of his or her 1,000 won savings or allowance and, thereby, caused a 100 won decease in that savings or allowance. But doing that would not cause a deficit; it would only cause a decease in his or her savings or allowance. That is why using 축내다 in that situation causes me some confusion. Instead, why not just use 쓰다 (to spend / to use) in that situation? It would make me feel much better.