Pooter I know from my brother and father, who were biologists, as a way of picking up insects by suction without harming them or sucking them into your mouth (Yech), don't know if that's a garden tool exactly, maybe it is something else as well.
Dibble I would guess to be what I call a dibbler, an old handle from a fork or spade usually, cut short and made pointed for making holes for planting. Historically in East Anglia they used 'dibbling sticks', two long sticks with a bullet shaped metal head held one in each hand and banged into the ground whilst walking along to make holes for the person following to plant wheat seed in.
Widger I hadn't heard before, mattock I think of as a 'common or garden' name for what Americans seem to call a 'heavy hoe'.