Cases of word usage

1) (in games such as football) the posts between which (the goal-mouth) the ball is to be sent in order to score; an aim of one's effort or ambition (goal)

2) an apparatus used for generating, amplifying and concentrating light waves into a powerful beam, used to cut metal and jewels, to aim weapons etc (laser)

3) an approach made (to a person) with the aim of starting discussions; a composition played as an introduction, especially to an opera (overture)

4) with little or no sense, aim or purpose (pointless)

5) to walk or travel without any definite aim or destination over or through (a country etc) (roam)

6) to hit, aim a blow at, (a person, thing); to stop working for an employer (in order to get more pay, better conditions etc) (strike)