"knall-" meaning in Swedish

{
  "etymology_text": "The word knalleffekt comes from the usage of fireworks and loud bangs (knall) in theatrical plays to astound the audience. The words knallhård, originally referring to stale bread, comes from \"hard as a knalle (“hardtack”)\". Later usage as a generic amplifier, for example when describing colors, is with reference to these.",
  "head_templates": [
    {
      "args": {
        "1": "sv",
        "2": "prefix"
      },
      "expansion": "knall-",
      "name": "head"
    }
  ],
  "lang": "Swedish",
  "lang_code": "sv",
  "pos": "prefix",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Pages using catfix",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 2 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Swedish entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "knall- + blå (“blue”) → knallblå (“very blue”)",
          "type": "example"
        }
      ],
      "glosses": [
        "strong, very"
      ],
      "id": "en-knall--sv-prefix-m46jXqpa",
      "links": [
        [
          "strong",
          "strong"
        ],
        [
          "very",
          "very"
        ]
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "word": "knall-"
}

{
  "etymology_text": "The word knalleffekt comes from the usage of fireworks and loud bangs (knall) in theatrical plays to astound the audience. The words knallhård, originally referring to stale bread, comes from \"hard as a knalle (“hardtack”)\". Later usage as a generic amplifier, for example when describing colors, is with reference to these.",
  "head_templates": [
    {
      "args": {
        "1": "sv",
        "2": "prefix"
      },
      "expansion": "knall-",
      "name": "head"
    }
  ],
  "lang": "Swedish",
  "lang_code": "sv",
  "pos": "prefix",
  "senses": [
    {
      "categories": [
        "Pages using catfix",
        "Pages with 2 entries",
        "Pages with entries",
        "Swedish entries with incorrect language header",
        "Swedish lemmas",
        "Swedish prefixes"
      ],
      "examples": [
        {
          "text": "knall- + blå (“blue”) → knallblå (“very blue”)",
          "type": "example"
        }
      ],
      "glosses": [
        "strong, very"
      ],
      "links": [
        [
          "strong",
          "strong"
        ],
        [
          "very",
          "very"
        ]
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "word": "knall-"
}