"-τις" meaning in Ancient Greek

{
  "forms": [
    {
      "form": "-tis",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "grc",
        "2": "suffix form"
      },
      "expansion": "-τις • (-tis)",
      "name": "head"
    }
  ],
  "lang": "Ancient Greek",
  "lang_code": "grc",
  "pos": "suffix",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Ancient Greek entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "πιθ-τις > πῐ́στῐς (pístis)"
        }
      ],
      "glosses": [
        "Earlier form of -σις (-sis), retained after dentals δ, θ, σ, τ"
      ],
      "id": "en--τις-grc-suffix-pfLY9fbS",
      "links": [
        [
          "-σις",
          "-σις#Ancient_Greek"
        ]
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "word": "-τις"
}

{
  "forms": [
    {
      "form": "-tis",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "grc",
        "2": "suffix form"
      },
      "expansion": "-τις • (-tis)",
      "name": "head"
    }
  ],
  "lang": "Ancient Greek",
  "lang_code": "grc",
  "pos": "suffix",
  "senses": [
    {
      "categories": [
        "Ancient Greek entries with incorrect language header",
        "Ancient Greek non-lemma forms",
        "Ancient Greek suffix forms",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "examples": [
        {
          "text": "πιθ-τις > πῐ́στῐς (pístis)"
        }
      ],
      "glosses": [
        "Earlier form of -σις (-sis), retained after dentals δ, θ, σ, τ"
      ],
      "links": [
        [
          "-σις",
          "-σις#Ancient_Greek"
        ]
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "word": "-τις"
}