とんとんwith a tap, with a knock, with a knocking sound, with a rap-tap, smoothly (proceed), without a hitch, without delay, even, equal, break-even

扉(とびら)をトントンとノックする。

Knock on the door with a tap-tap. {with a tap, with a knock, with a knocking sound, with a rap-tap, smoothly (proceed), without a hitch, without delay, even, equal, break-even}

身軽(みがる)な彼(かれ)がトントンと階段(かいだん)を登(のぼ)った。

The nimble him climbed the stairs with a knocking sound. {with a tap, with a knock, with a knocking sound, with a rap-tap, smoothly (proceed), without a hitch, without delay, even, equal, break-even}

取引(とりひき)先(さき)との決(き)め事(ごと)は順調(じゅんちょう)にトントンまとまった。

The arrangements with the client proceeded smoothly without a hitch. {with a tap, with a knock, with a knocking sound, with a rap-tap, smoothly (proceed), without a hitch, without delay, even, equal, break-even}

ドアをトントンとノックしたら家主(やぬし)が出(で)てきました。

When I knocked on the door with a tap, the landlord came out. {with a tap, with a knock, with a knocking sound, with a rap-tap, smoothly (proceed), without a hitch, without delay, even, equal, break-even}

工事(こうじ)がトントンと進(すす)み、もう完成(かんせい)まで間近(まぢか)なのだそうです。

The construction has been proceeding smoothly, and it seems it is almost finished. {with a tap, with a knock, with a knocking sound, with a rap-tap, smoothly (proceed), without a hitch, without delay, even, equal, break-even}