Merriam-Webster Collegiate Dictionary - dink

 I. noun  Etymology: by shortening & alteration  Date: 1903 dinghy  II. noun  Etymology: ~ to hit with a drop shot, probably of imitative origin  Date: 1939 drop shot  III. noun  Etymology: perhaps from ~, disparaging name for a Vietnamese  Date: 1974 slang nitwit, jerk, nerd  IV. noun  Usage: often all capitalized  Etymology: double income, no kids  Date: 1986 a couple with two incomes and no children; also a member of such a couple