The participle fans is widespread, and the Romans themselves made a clear
and explicit connection between the verb and the word infans. Infans also
means "not speaking" - see the example from Aulus Gellius below.
Here's another simple example:
Plautus Pers 2:1:7 meum ingenium fans atque infans tu edidicisti
And examples of the links the Romans made (showing analogy between infans
and the verb is more than probable):
Varro: "That person is said to speak ("fatur"), who as a man first emits a
sound with meaning. For that reason, before they do that, children are
called "infans".
Aulus Gellius "The son of Croesus, at an age when he should have been able
to speak ("fari"), was still "infans".
The word can't mean "an infant" here.
St Augustine (all right, a bit late, but nonetheless .) I wasn't an
"infans" who did not speak ("farer").
Peter
>The other example is <haec fantem>, from an elegy by Sextus Properius,
>occurring also in Valerius Flaccus' "Argonautica". Both sources can be
>googled up easily.