Trading, a.
1. Carrying on trade or commerce; engaged in trade; as, a trading company.
2. Frequented by traders. [R.] "They on the trading flood." Milton.
3. Venal; corrupt; jobbing; as, a trading politician.
Shades of meaning
Fernald has no entry of its own for trading; he lists it under business.
Where he writes about it:
Trade or trading is, in general, the exchanging of one thing for another; in the special sense, a trade is an occupation involving manual training and skilled labor; as, the ancient Jews held that every boy should learn a trade. — from business