BSL - British Sign Language - is a sign language used between and with people who are deaf. It is a language in its own right and it is not possible to sign BSL at the same time as speaking English. BSL has its own grammar, and the order in which you sign words may be different from the order in which you might say the same thing in English. Sign Supported English (SSE) is a method of using BSL signs at the same time as speaking English.
If a sign is tagged on this site as being present in BSL, this means that the manual part of the sign appears to be present in at least one dialect of BSL - however it might not be the most common way that BSL users might express the English word/meaning associated with it here. If you are looking for BSL signs, you will probably find a site like signbsl.com or Spread the Sign more useful.
