We developped a web app for ascribing verbal descriptions to expressive audiovisual utterances. These descriptions are limited to lists of adjectives that are either suggested via a navigation in emotional latent spaces built using discriminant analysis of BERT embeddings or entered freely by subjects. We show that such verbal descriptions collected on-line via Prolific on massive data (310 participants, 12620 labelled utterances up-to-now) provide Expressive Multimodal Text-to-Speech Synthesis with precise verbal control over desired emotional content