The function takes an input string and returns the length of that string in word form (e.g. 'four' instead of 4).

[CODE]:
```python
def string_length_to_word(input_string):
    num_to_word = {1: "one", 2: "two", 3: "three", 4: "four", 5: "five", 6: "six", 7: "seven", 8: "eight", 9: "nine", 10: "ten"}
    length = len(input_string)
    return num_to_word.get(length, "Input length not covered")
```