Actually the word for "to call out, shout" isn't clamo, it's clamere.

Actually, the standard way to list a Latin verb in a Latin-English dictionary is by the first person present indicative form. (This is called the lemma in lexicography, and there are three other forms usually listed, from which, theoretically, one can reproduce the entire verbal paradigm: the infinitive clamare, the first person present perfect indicative clamavi, and the neuter singular past participle clamatum.) (Traditionally any other irregular forms are given after these four, but before the entry proper starts.) Dictionaries gloss the verbal entry with the English infinitival form. Other languages, have other lexicographical standards, e.g., German dictionaries list verbs by the infinitive, Sanskrit by the root. In the end, good enough for Lewis and Short, good enough for me, but I'm not saying you all have to use it, just why I do.

Ceci n'est pas un seing.