What is the meaning of Secundus?

second, the ordinal number after prīmus (first) and before tertius (third)

next, following

according to (with object in accusative case)

second

secondary, subordinate, inferior

favourable, fair (of weather, seas)

fortunate, lucky, victorious, successful (of battle--secundis proeliis)

propitious, favorable, fortunate

Source: wiktionary.org