"-ιστής" meaning in Grec ancien

{
  "categories": [
    {
      "kind": "other",
      "name": "Suffixes en grec ancien",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Grec ancien",
      "orig": "grec ancien",
      "parents": [],
      "source": "w"
    }
  ],
  "derived": [
    {
      "lang": "Français",
      "lang_code": "fr",
      "word": "-iste"
    }
  ],
  "etymology_texts": [
    "Les mots en -ιστής sont des dérivés en -τής, -tês de verbes en -ίζω, -ízô. Voir -ισμός, -ismos qui nous donne -isme."
  ],
  "lang": "Grec ancien",
  "lang_code": "grc",
  "pos": "suffix",
  "pos_title": "Suffixe",
  "raw_tags": [
    "-ιστής, -istês"
  ],
  "senses": [
    {
      "glosses": [
        "Suffixe nominal, -iste."
      ],
      "id": "fr--ιστής-grc-suffix-36c5KcgX"
    }
  ],
  "tags": [
    "masculine",
    "morpheme"
  ],
  "word": "-ιστής"
}

{
  "categories": [
    "Suffixes en grec ancien",
    "grec ancien"
  ],
  "derived": [
    {
      "lang": "Français",
      "lang_code": "fr",
      "word": "-iste"
    }
  ],
  "etymology_texts": [
    "Les mots en -ιστής sont des dérivés en -τής, -tês de verbes en -ίζω, -ízô. Voir -ισμός, -ismos qui nous donne -isme."
  ],
  "lang": "Grec ancien",
  "lang_code": "grc",
  "pos": "suffix",
  "pos_title": "Suffixe",
  "raw_tags": [
    "-ιστής, -istês"
  ],
  "senses": [
    {
      "glosses": [
        "Suffixe nominal, -iste."
      ]
    }
  ],
  "tags": [
    "masculine",
    "morpheme"
  ],
  "word": "-ιστής"
}