1. 试销：on account赊帐 | on approval试销 | on board已装船

2. (商品)供试用的;包退包换的：on a diet 节食 | on approval (商品)供试用的;包退包换的 | on condition that 如果

3. (货物)供试用的,包退包换的：9、amortize 分期偿还(欠款的利息) | 10、appraisal of real estate 不动产估价 | 11、on approval (货物)供试用的,包退包换的

4. 供试用的(看样试用后决定是否购买), 包退包换的：fringe benefits designed to offset low salaries.用以补偿低工资的额外福利 | on approval供试用的(看样试用后决定是否购买), 包退包换的 | off the shelf 现货供应 不用定制的

adv

1. for examination (with an option to buy)

e.g. they took the VCR on approval