FullDefinition

FullDefinition[symbol] prints as the definitions given for symbol, and all symbols on which these depend.

FullDefinition["symbol"] prints as the definitions given for the symbol named "symbol" if it exists, and all symbols on which these depend.

FullDefinition[patt] prints as the definitions given for the symbols whose names textually match the arbitrary string pattern patt, and all symbols on which these depend.

FullDefinition[{spec1, spec2, ...}] prints as the definitions given for the symbols that are equal to or whose names match any of the speci, and all symbols on which these depend.

Examples

Define a function and show its full definition:

f[x_] := g[x] + 1;
g[x_] := x^2;
FullDefinition[f]

Please visit the official Wolfram Language Reference for more details.