Abarim Publications' online Biblical Hebrew Dictionary
The noun קנץ (qanas) occurs only once in the Bible, namely in Job 18:2, and it's unclear what it means: "How long will you qanas for talkings?" It's also unclear where it comes from although a comparable verb in Arabic means to hunt, snare or capture.
NAS, ASV and Darby go with "hunt" and JSP with "snares". NIV, KJV and Young appear to assume relations with the verb קצץ (qasas), meaning to remove by cutting off, and translate our noun with "end". But the assumed link between these words isn't very convincing and modern commentators have abandoned it.
The verb קנז (qanaz) isn't used in the Bible at all, and it's not even sure that it ever existed in Hebrew. The only reason why it's suspected to have existed is because of two Biblical names that are derived from it.
It's generally assumed that both קנז (qanaz) and קנץ (qanas) are transliterations of the Arabic original that means to hunt, snare or capture. The difference in spelling may thus be due to differing dialects or the tastes of the transliterators.