Random Puzzles 

Workings

Hint
These are all Greek letters.

Answer
θ (theta).

Reasoning
These are all Greek letters, and they are:

   xi, chi, theta, psi, pi, phi

They all sound similar to each other, except θ.

Workings

Hint
The answer is in the words given.

Answer
Slow.

Reasoning
Take the third letter of the first word
   + the second letter of the second word
      + plus the first letter of the first word
         + plus the fourth letter of the second word.

Double-Checking
3-1- [1234] -2-4
s-f- [fast] -a-t
o-s- [slow] -l-w

Workings

Hint
What does each one do?

Answer
Door.

The others are used to cover windows.

Workings

Hint
The first letters of the words are: L, C, E, E, A, A, L, S, F, G, S, A, C, C, M.

Answers
---rnt = learnt ---few = curfew ---ryo = embryo ---yme = enzyme ---rak = anorak ---urd = absurd ---ynx = larynx ---mpi = scampi ---hom = fathom ---ovy = groovy ---lpt = sculpt ---hma = asthma ---voy = convoy ---web = cobweb ---mur = murmur