See:
SEFOS# help first_word
where first_word is the first word of the command string.
For example, to get help on the show clock command, type:
SEFOS# help show EXEC commands : show access-lists [[{ip | mac}] <access-list-number (1-65535)> ] [Desc]: Display access lists configuration show aliases [Desc]: Displays the aliases. show arp spoofing [interface <ifXtype> <ifnum>] [Desc]: Shows the arp spoofing details. ... show clock [Desc]: Displays the system clock. ... show wildcard {mac-address <mac_addr> | broadcast} [switch <context_name>] [Desc]: Displays wildcard Mac Address Table entries SEFOS#