The Free On-line Dictionary of Computing (30 December 2018):
Strict enforcement of type rules with no
exceptions. Incorrect type usage can be detected either at
run time or at compile time. Strong typing catches more
type errors than weak typing, resulting in fewer hard
errors. In a strongly typed language, conversion between
types requires the use of explicit conversion functions
("casts") as opposed to implicit type coercion.
Typing strength is a continuum; ML is more strongly typed
than Java, which is more strongly typed than C.
Strong or weak typing is independent of the choice between
static typing and dynamic typing. Among strongly typed
languages, Ada, Java, Haskell and ML are statically
typed, whereas Python and Ruby are dynamically typed.