A clump is a group of similar things, very close together and hard to separate. The picture is of a clump of yellow flowers.
Cis forClydesdale
Coal is a type of black rock, made almost entirely of carbon. It is formed from old plant matter being squashed by the gradual movement of the earth over a very long time. Coal can be burnt, and is often used as the fuel for power plants. Coal is dug out of the ground, from coal mines.
Coal is not the same as charcoal, which is just the black residue after wood is burnt.
A coat is a warm top you wear over other clothes. A coat is very similar to a jacket but coats are usually longer. The word coat can also be used to describe an animal's fur.
Cis forCobblestones
Cobblestones are stones that were used to pave streets before concrete and asphalt were invented. They were typically smooth stones found in a riverbed. Because the stones could be all different sizes and were placed so they fit together without gaps, they have given rise to the phrase "cobbled together".
Cobras are a kind of venomous snake found in Africa, India, the Middle East and Indonesia. They rear up and flatten out their neck like the snake in the picture when they are scared.
Cobras are the snake of choice for snake charmers, who seem to hypnotise a snake by playing a musical instrument in front of it.