peter wrote:1 The word on its own, "compost" means the output of the compost heap, composted, i.e. rotted organic material.
2 The word with a suffix, "Seed compost", "Potting compost", i.e. a mixture of materials suitable for the purpose denoted by the suffix.
I have noticed a trend in recent years where the two seem to have become confused by various people, to the extent of some people merely sieveing the output of their heap, placing it in trays to germinate seeds in, or, in pots to grow plants in.
Are these two things really so distinct, or is it our forgetting what is in the bag from the garden centre that makes it seem so different ? What is peat but partially decayed organic matter ? Certainly what goes into commercial peat free potting composts is to a large degree composted organic matter. And believe it or not, if you sieve what you get from your compost heap, it grows tomatoes quite nicely.