Something is leaning if it has tilted from being vertical. The gravestone in the picture is leaning quite badly.
You might also lean on something if you put some of your weight on it, for example when you lean up against a lamp post.
To leave is to go away. The man in the picture is about to get into a car to leave.
Led is the past tense of lead. The man in the picture has led the camel along.
A ledge is similar to a shelf, being fairly narrow and horizontal. Ledges are generally built into a building, either for decoration or for practical reasons, like a windowledge.
Scientific name: phylum: annelida, subclass: hirudinea
Leeches are in the same family as earthworms. Not all leeches are bloodsuckers, but the ones people are most familiar with are. They grow to around 2-5cm long but some species reach 30cm. Leeches live in damp, swampy areas.
Leeches have adapted one end of them into a sucker, so they can attach to a host. They inject anaesthetic in as they bite, so the host cannot feel them, and then an anti-clotting agent so the host's blood flows freely. Leeches stay stuck to their host until they are full, then they drop off.
